(Bloomberg) — The smoke from California’s deadliest fire is so thick that it’s blotting out the sun and lowering surface temperatures by as much as 10 degrees Fahrenheit (6 Celsius), according to the U.S. National Weather Service.
The area around the Camp Fire is so bad that all those venturing outdoors in the cities of Gridley and Chico without a surgical-grade respirator are putting themselves at risk, according to AirNow, the U.S. air-quality-tracking agency created by the Environmental Protection Agency.
The air in the immediate vicinity of the fire is considered “hazardous” — the worst it can be — and the poorest in the U.S. AirNow has an “unhealthy” rating for the air from Sacramento to Livermore.
The smoke is so thick “it prevents the sunlight from reaching the surface,” said Hannah Chandler-Cooley, a National Weather Service meteorologist in Sacramento. “It prevents surface heating.”
The air quality was only a little better in San Francisco, and many commuters riding trains into the city donned masks Thursday morning. The iconic Bay Bridge, viewed from the waterfront, seemed to get swallowed up in the gray smoky haze drifting south from the fires. Along busy Market Street, a smattering of people wore masks, though most pedestrians were outdoors without one.
Poor air quality will likely linger through next week before a weather pattern shifts, potentially blowing the smoke to the east, Chandler-Cooley said by telephone. Things could improve sooner if firefighters manage to contain more of the blaze, which has scorched 140,000 acres, destroyed thousands of homes and killed at least 56 people. High temperatures in the Chico area reached the upper 50s Wednesday, below the normal 60s, she said.